Anode for mercury-vapor rectifiers



Oct. 12 1926.

J. KUBLER ANODE FOR MERCURY VAPOR RECTIFIERS Filed Jung 6, 1921 Patented oer. 12, 1926.

UNITED STATES PATENT OFFICE.

JOHANN Kfl'BLER, F IBADEN, SWITZERL UD, ASSIGN'OR T6 AKTIENGESELLSCHAI FT BROWN, BOVERI &, 0111., OF BADEIN', SWITZERLAND.

ANODE FOR MERC U 'RY-VAPOR RECTIFIERS.

' Application filed June 6,- 1921, Serial No. 475,483, and in Switzerland June 18,1920.

In the known cylindrical or hollow cylindrical forms of anodes for mercury-vapor rectifiers. it has been observed that thepoint whence the ele tric arc emanates. creeps up- Wards, that is to say towards the inlet insulator of the anode. This is due to the fact that the electric arc has a smaller ohmic resistance than the iron anode. and by reason of a lengthening of the light arc in com-- bination'with an equal shortening of the metallic path for the current through the.

anode material. there is produced automatically a diminution of the total resistance of the direct current circuit.

According to this invention the creeping of the point of emanation of the electric are is obviated by constructing the anode in Such a manner that the rising of the point of emanation of the electric arc'will produce an increase in the total resistance of the direct current circuit. Namely, whereas hitherto the connection of the anode to the supply circuit has been situated approximately at its highest point, now according to this 2 invention the current is supplied to it approximately at its lowest point. that is to say at its point situated. nearest the cathode.

K'An example of a rectifier anode constructionaccording to the invention is illustrated in the accompanying drawing, which representsasection of part of a rectifier with an inserted anode. In the drawing the anode is formed asa thin hollow cylinder aof iron .which is closed at its-lower end and has at the lowest pointof its interior a thickened portion c. The current supply rod 1;" is" screwed into this thickened. portion.

For the purpose of keeping the ohmic reble compared with the-ohmic resistance of the path through the anode casing 'a, the

rial, for instance, copper.

sistance of the path of'the current through" the centre of the anode as small as possi "I he annular cavity d between the anode casing a and the supply rod 6 maybe utilized for the. cooling of the anode,'and is I cooling medium, and its circulation is assisted, by convection. In many cases however. the good. conductionof'heat through the thick copper rod b will suffice.

The entire anode is surrounded by the insulator 'f at the point where it passes through the wall e ofthe rectifier vessel. The rod 1) and anode a, 0, may of course be made in one piece; Other forms of anodes besides those shown in the drawing' can be readily designed.

What I claim is:-- v r 1.-An anode for a mercury vapor rectifier comprising a hollow cylinder closed at 66 the end nearestthe cathode and means for connecting a conductor directlyto the closed end.

2. An anode for a mercury vapor recti-, fier and a conductor for connecting same to 70 a supply circuit characterized by the feature that theanode -is "formed as a hollow cylinder closed at the end nearest the cathode, with a conducti'ngrstub rising in'the interior of the cylinder from said closed end and that the said conductor is connected mechanically and electrically to said stub.

3. In the anode as defined in claim 1 means for introducing an insulating cooling medium between the interior of said hollow cylinder and said conductor. 4. A combination as claimed inclaim 2 with the additional feature that the said conductor is screwed directly into the 'said 3 In testimony whereof I have signed my name to this specification.

JOHANNV KUBLER. 

